Piston for internal-combustion engines



July 8, 1930. s. A. WINSTON 1,770,332

PISTON FOR INTERNAL COMBUSTION ENGINES Original Filed Aug. 15, 1927 2-; 2 j 7 J 4 i 4 :1 2

ATTORN EY Patented July 8, 1930 SAMUEL a wrns'ron, or ocnnnrann, SANTA MONICA, onnrro'nnrn rrs'roiv non rn'rnnnnn-oomnusrron nlveinns Application filed August 13, 1927, Serial No. 212,770. ReneW edApril 7, 1930.

This invention relates to a piston for .in-

ternal combustion engines. 'Iheinvention is designed to reheve the d1flicult1es incident to expansion and contraction of pistons due to avoid stoppage of the engine due to sticking of the piston and the slap and knocking due to excess clearance under heating and cooling. ,I avoid these difficulties by producing a piston of the trunk type hollow in the interior, the upper part of which above the wrist pin where the oiling groove and rings are provided having an elastic skirt having an annular cored out recess in the transverse plane of the wrist'pin by which the cylindrical skirt is rendered flexible and elastic to yield under the variations of temperature,

and skirt being provided with a plurality of axial slots affording a multipart sectional 2e skirt which can yield to compensate for eX- pansion and contraction. lhe skirt sections are formed by a plurality of symmetrically related slots in axial drilled .holes in bosses forniingvpart of the piston. Av construction 'ofthis kind affords complete opportunity for yielding and avoidance of sticking of the piston to stop the engine, and by reason of the elasticity of the skirt segments affords aperfect compensation for expansion and con- 3 traction under variations of temperature,

rendering a smooth action of-the engine always possible.

The invention therefore consists of a trunk type of piston provided with'an annular recess above the plane of the wrist pin and an annular opening within the outer wall of the piston, and a plurality of symmetrically related slots parallel to the axis to afiford resil- 46 ient compensation for expansion and contraction. It comprises also more specific features, the novelty of which will be hereinafter fully described and definitely indicated in the appended claim.- In the accompanying drawing illustrating my invention: v Figure 1 is a face view of a piston embodying my improvements.

Fig. 2 is a sectional View at right angles 5 to that of Fig.1.

variations of temperature in engines, and to 1 tion,

,"Figure 3 is asectional view'at right angles to that taken in Figure 2.

Y Figure 4 is a horizontal section on the plane 4-4 of Figure 2; I

Referring now in detail to the drawings, 1

represents a hollow pistonprovided in the usual way with a plurality of annular grooves 2 close to'its upper margin. I provide a pair of pin bosses 3, 3 to afford asecure mounting for the wrist pin 4 on which a rocking pitman maybe mounted to deliver. the power generated bythe'movements of the piston. The, grooves 2 form receptacles forsoil wiping and rings of usual construc- V, r v 5 A distinctive feature of my invention exists 1n forming an annular slot, as indicated at 5, immediately below the oil ring groove and I'form in vertical alignment in communication with this slot oppositely disposed pairs of open sided narrow vertically arranged recesses 6 whose rear walls connect the two sections formed by the slot, the head 1 of the piston and the skirt 7, these recesses 8 being formed in any suitable way, as for example, by coring in casting the piston. This leaves the skirt 7 connected'to the body of the piston by the rear walls which are thin and permits the skirt to yield elastically with reference to the upper part 01" the piston body, and I form in the skirt a I plurality of symmetrically related segments 8, 8 8", 8 extending above the plane of the wrist pin, and the several segments are yield able relatively to each other by-reason of tubular members 9 slotted through the skirt wall as at 10 and as best shown in Figure 4. By this construction the several sections of the skirt are rendered highly elastic and may yield readily under variations of tempera ture and relative changes of clearance be- I tween the piston and the walls of theexplosion chamber, I preferably strengthen the V bearings of the wrist pinby'tapered ribs 11, 11 which add strength to the joint between the body and the skirt whilestill leaving abundant freedom for elastic yielding in the skirt section of the piston. I provide this section with less clearance than the body of the piston above the plane of the wrist pin. 10

The latter portion may have a clearance of .005, whereas the lower portion or skirt may have considerably less. In operation the piston picks up oil from the cylinder walls and becomes self-lubricating, while all excess oil drains back into the crank case, thereby aflording proper lubrication.

Having thus described my invention, what I claim as new and desire to secure by Letl ters Patent is:

A piston having an annular slot formed therein adjacent its upper end to provide a head and a skirt, said head being formed with ring grooves, said skirt being formed with vertically arranged narrow recesses in communication with the slot at their upper ends and in a manner whereby the rear wall of the recesses connect the skirt with the head in spaced relation with respect thereto, said recesses being formed in oppositely disposed pairs and having open sides communicating with the interior of the piston, vertically disposed tubular members formed in said skirt and being slotted with the slotvextending through the skirt to provide yieldably mounted sections of said skirt, and said tubular members extending from the upper to the lower ends of the skirt.

In testimony whereof I afiix my signature.

SAMUEL A. VINSTON. 

